heh, Jerry ...

... I learned it all to you, and Iceberg, and the rest of the clever guys on the forum!
I think I used some of your old pictures, and cleaned 'em up in Paint.
As for the splitters... Sorry, I don't know the correct term for the ones needed.
And frankly, I don't even
like splitters.
But I did want to correctly identify what ya needed.
Just don't make me shop for 'em.
So, being one of the relatively few DishPro LNB Guru's, what do you think about using the 105º LNBs?
How would they likely perform in this situation?
The OP presented a pretty difficult challenge.
Some of the other suggestions are quite inspired - sacrificing certain transponders.
Hey, if that's acceptable, go for it!
One other though I had, was to use the existing GeoSat Mini's and access them through similar splitters, so they got the higher of the two voltages supplied to them.
That would mean they would put out Horizontal if either receiver requested it, otherwise they'd put out Vertical.
So, only if both receivers accessed one of the minis, and requested different polarity, would there be a conflict.
(well, not an electrical conflict, just a logical one - both would get Horizontal)
...and you might want to move the mini to the prime location, if it'd help.
Only the OP would know whether that would be acceptable.
edit: Oh, rereading what I posted, it just occurred to me that you could use the existing Mini's where the DishPro LNBs are shown in the drawing above.
Other than the conflict described, you'd have to change the switch setup to:
diseqc 1:
129º, 12v=V, 18v=H, 22k doesn't matter (could use Universal Mini's)
diseqc 2:
123º, 12v=V, 18v=H, 22khz off
diseqc 2: .
97º,, 12v=V, 18v=H, 22khz on
diseqc 3:
101º, 12v=V, 18v=H, 22k doesn't matter (could use Universal Mini's)
diseqc 4: reserved for future
I must say, I'm not really a fan of any of the ideas presented so far. . .